Laser range finders project a laser beam to measure the distance to a target object. Traditional laser range finders are relatively compact, while still providing relatively accurate distance measurements. Therefore, traditional laser range finders are used in a variety of applications, such as sporting applications (e.g., golf and hunting), construction applications (e.g., surveying) and military applications (e.g., target acquisition).
Traditional laser range finders commonly employ the “time of flight” method for measuring distance. A time of flight laser range finder typically includes a laser and a detector. The laser projects a laser pulse toward a target object and initiates a clock. The detector detects backscattering as a result of the laser pulse hitting the target object. The clock is tolled upon initial detection of backscattering. The time difference between projection of the laser pulse and initial detection of backscattering is the time of flight (i.e., the time it took for light to pass from the laser range finder, to the target object, and then back to the laser range finder). The distance to the target object is then calculated by multiplying the time of flight by the speed of light and dividing by two (the distance to the target object is half the distance traveled).
Since traditional “time of flight” laser range finders measure distance based on the first detection of backscattering, such laser range finders are limited to detecting only one object (i.e., the first object within the path of the laser pulse). Furthermore, only the distance to the leading edge of the target object is measured. Therefore, the utility of traditional “time of flight” laser range finders is limited.
Accordingly, those skilled in the art continue with research and development efforts in the field of laser range finders.